Various methods for using a high performance server uninterruptedly in an environment where a plurality of servers are used like a data center are developing. One of them is to double supply power to a server. This method supplies separate power and prevents abnormal power supply even when a problem arises from one power supply system.
However, in order to double supply power, a PDU should be connected to different power sources and thus two PDUs are physically required. Accordingly, a double power system is required and thus an operator should add the same PDU set as the existing PDU set.